Efficient image and video re-coloring for colorblindness

There are about 8% of men and 0.8% of women suffering from colorblindness. These viewers have difficulty in discriminating several colors, and thus many colorful images and videos that have high qualities for normal viewers may not be readily perceptible for them. In this paper, we propose an efficient re-coloring approach which can modify the colors of images and videos to enhance their perceptibility for colorblind users. Given an image, the re-coloring is accomplished by two color rotation steps in CIELAB color space. We first perform a local color rotation such that information of b^* axis can be enhanced, and then adopt a global color rotation to refine the results. We will show that this method is simple yet effective, and it is able to outperform the traditional re-coloring algorithms in both performance and computational efficiency. We apply the method to process video frames and adopt several strategies to further reduce computational cost to realize real-time video re-coloring. We also explore the structure information of video data to avoid the color inconsistency problem. Specifically, we enforce the color mapping function to be identical in each shot and vary smoothly in adjacent shots. We conduct experiments on real-world images and videos with diverse content, and empirical results demonstrate the effectiveness of the proposed methods.